1. Field of the Invention
The present invention relates to an information recording apparatus and method for recording information on a plurality of recording media.
2. Description of the Prior Art
For recording and reproducing music information, there has generally been broadly used a cassette tape type recording medium. Particularly, in the case of recording long music information or a plurality of music information, so-called double cassette deck apparatus, which is equipped with two cassette deck portions, is broadly used. In these days, in addition to the cassette tape system, an MD (Mini-Disc) system is getting popular. MD is used with a magneto-optical recording and reproducing apparatus, and is characterized by its small size, light weight, remarkably quick accessibility in reproduction and insusceptibility to erroneous jump due to external shocks because of an internal shock-proof memory. It is expected that new functions making the best use of the above advantages are developed.
FIG. 1 is a block diagram illustrating the configuration of an information recording and reproducing apparatus for use with MD. The MD 21 includes a magneto-optical disc body having a magnetic layer, and a cartridge (not shown) for protecting the magneto-optical disc body. When installed in the information recording and reproducing apparatus, the MD 21 is held by the spindle motor 1 by means of a magnet. The pickup 4 includes the optical head 3 which irradiates a laser beam onto the rotating magneto-optical disc and receives a return beam from the disc to obtain an RF (Radio Frequency) signal, and is carried by the carriage 14 movable in the radial direction of the disc. The magnetic field modulating head 2, which applies the magnetic field modulation to the magnetic layer of the disc to record information thereon, is also movable in the radial direction of the disc by means of the head driver 5. The servo controller 8 controls the performances of the driving systems of the spindle motor 1, the pickup 4 and the carriage 14.
At the time of reproducing information from a recordable MD, the RF signal is amplified to a certain level by the RF amplifier 7, and the address decoder 6 detects the wobbling frequency from the RF signal, thereby making it possible to detect the position on the disc with respect to time, even if no information has been recorded thereon. The EFM encoder/decoder 9 extracts the EFM signal from the RF signal amplified by the RF amplifier 7 at the time of reproduction, and converts the information to be recorded into the EFM signal to control the output of the magnetic field modulating head 2 at the time of recording. The DRAM controller 11 temporarily writes the information read out from the disc into the DRAM 12 at the speed about five times larger than the data reading speed, according to so-called FIFO (First-In-First-Out) method, to control the data writing and reading by the DRAM 12.
The analog signal supplied from an external device at the time of recording is converted into the digital signal by the ADC (Analog-to-Digital Converter) 15, and is then compressed by the data compression encoder/decoder 13 such that the data amount is reduced to 1/5 of its original amount by utilizing the audibility threshold characteristic and masking effect. On the other hand, the signal read out from the MD 21 at the time of reproduction and then EFM demodulated by the EFM encoder/decoder 9 is subject to the data expansion by the data compression encoder/decoder 13, and then converted to the analog signal by the DAC (Digital-to-Analog Converter) 16 to be outputted. The system controller 30 functions to control each components in the information recording and reproducing apparatus. The system controller 30 also receives the signal from the key input unit 18 which receives operational instructions from users (from external), and controls the display unit 17 which displays information recording and/or reproducing condition of the apparatus.
At present, there is a need for a player system employing two MD decks like the double cassette player mentioned above. It is of course desired to achieve an effective use of the two MD decks in recording information on the MD. For example, in the case of recording many songs on two or more MDs or recording radio broadcasting program for which the playing time of the songs are generally unknown, the user has to manually operate, by himself, the recording apparatus with close attention to appropriately record the songs without interruption or break of the recorded song.